It is necessary for an engine of a motorized implement to be both lightweight and compact in order for the motorized implement to be carried by an operator during operation. Simple two-stroke engines that are small and lightweight in structure, and in particular, two-stroke reverse flow type engines such as the engine disclosed in Unexamined Japanese Patent Application KOKAI Publication No. H11-315722 are therefore commonly used as engines for motorized implements.
However, in recent years, it has become necessary for the engines to have low gas emission characteristics. Reverse flow type two-stroke engines that have low emission characteristics are a result of appropriate control of scavenging flow from scavenging ports into a combustion chamber. A way of internally shaping a scavenging path is therefore desireable in order to control the scavenging flow. When the scavenging path overhangs outside of the cylinder, it invites larger engine dimensions. Manufacturing costs also increase due to the complexity of the shape of the scavenging paths when formed within a cast cylinder block.